


wear your heart around my neck

by Evandar



Category: Yu-Gi-Oh! Duel Monsters (Anime & Manga)
Genre: Anniversary, Consensual Underage Sex, Don't copy to another site, Established Relationship, Extremely Underage, Incest Makes Marriage Taboo, M/M, Secret Relationship, Sibling Incest
Language: English
Status: Completed
Published: 2019-07-28
Updated: 2019-07-28
Packaged: 2020-07-24 19:15:02
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,391
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20019634
Author URL: https://archiveofourown.org/users/Evandar/pseuds/Evandar
Summary: Between Pegasus stealing their souls and the Big Five trying to kill them, they miss their anniversary.





	wear your heart around my neck

**Author's Note:**

  * For [LuciferxDamien](https://archiveofourown.org/users/LuciferxDamien/gifts).



> LuciferxDamien, I really enjoyed writing for you. I hope you like the result!
> 
> This takes place post-Legendary Heroes arc.

He watches the line of Seto’s shoulders as his brother effectively shoos Yugi and his friends out of the building. Seto is tense. He’s a very private person, and a very proud one, and the last few months - first Pegasus and now this mess with the Big Five - have brought other people - outsiders - dangerously close to their personal lives. Worse, Seto has actively needed to be rescued by them both times, which will _definitely_ be upsetting him. But this time, at least...

“Tell me you got everything,” Seto says once they’re alone again. 

“Of course I did!” Mokuba replies, indignant. Just because he had to ask for help (again) doesn’t mean he didn’t know what he was doing. All the evidence they needed to put the Big Five in their place is securely stored away. He hands over the flash drive with all the files needed to prove it - the corruption, the assassination attempts. All of it. There's a second copy stored on their private server, and he has a third squirrelled away on an external hard drive at the bottom of the laundry basket. He’s been _thorough_.

He wants these bastards gone. _Permanently._. They tried to kill Seto this time, not just seal his soul away. They wanted him dead and for that, Mokuba will personally make sure they’re annihilated. 

Seto’s hand brushes over the top of his head. Long fingers tangle into his hair and Mokuba tucks himself eagerly against Seto’s side. He tilts his head back, looking up at his brother. Seto is watching him. There’s a slight curve to his brother’s mouth; a softness in his eyes that’s for Mokuba alone. 

“Good,” Seto says quietly. “I knew you could do it.”

Any upset Mokuba might have felt is immediately soothed away. He tightens his grip on Seto’s waist and presses his face into his ribs. 

“I was worried,” he says, and even though his voice is muffled, he knows Seto can hear him. “I was really scared, Seto.”

“I know.” Seto’s fingers are so gentle, scratching over his scalp and running through his hair, sending shivers down his spine. 

Mokuba huffs softly, lifting his head to look his brother in the eye. 

“You owe me a proper anniversary,” he says. “This one _sucked_.”

...

He’s been in love with Seto for as long as he can remember. From his first memories, Seto has been there: bright and brilliant and protective and perfect. There’s no way that he couldn’t have loved him, not when they’re everything that each other has ever needed. Even so, he knows that it’s not normal. He knows that they grew up too close and too twisted together, ending up co-dependent in ways they shouldn’t be. He _definitely_ knows that he can never, _ever_ admit the truth of their relationship to anyone - not without destroying them both in the process - and Seto is far, far too important to him to even dream of risking it. 

He still wants to scream it from the rooftops, though. Seto is _his_. 

He sprawls against Seto in the bath. The water is hot enough to have brought a flush to his brother’s face, though it could also be from the kisses Mokuba has been trailing along Seto’s neck and collarbone. He can feel Seto hard and hot against his thigh; can feel his hands skimming lower and lower down the length of Mokuba’s back, but there’s no urgency in Seto’s touch. He’s tired - they both are - and over-stressed. But it’s been months since they last did anything more than kiss, since before Pegasus’ island, and Mokuba isn’t about to let this chance to be with his brother slip away. 

He may be tired, but he’s horny too, damn it. 

Seto’s fingers brush over the dimples at the base of his spine and skim downwards, lightly racing the curve of Mokuba’s arse under the water. He shifts, sliding up Seto’s body to press kisses to his jaw. Seto turns his head and kisses back, parting his lips and swiping his tongue along the seam of Mokuba’s mouth. Mokuba whines softly, letting Seto’s tongue sweep in even as the hand at his backside finally - finally! - grips tighter, hauling him close. 

Sometimes, when they do this, it’s all heat and breathless need. It’s Seto’s cock fat and heavy on his tongue as he makes his brother lose control, the salt-bitterness of his release and the way Seto touches him afterwards: gentle caresses and tender words that are reserved for Mokuba alone. 

He knows that Seto feels guilty about their relationship sometimes. He can see it in his eyes. But, he’s pretty sure that Seto’s guilt is more because of his age than the incest - after all, Seto made the same vows he did and with equal sincerity, and he’s worn his locket every day since, just like Mokuba has. So while he might be twitchy about Mokuba’s age sometimes, the commitment has already been made. They’re damn well _married_ no matter what the law says. And besides, it’s not like they rushed into anything - Seto is so determined to never hurt him that it’s frustrating sometimes. 

Mokuba _wants_ him. He wants things that he didn’t know existed before he looked them up on the internet. Mostly, he wants the anniversary sex that he’s been denied for the last _three days_ because Seto was busy being an _idiot_ and the board of Kaiba Corp is entirely made up of _arseholes_. 

He pushes his hips suggestively against Seto’s lower belly, rubbing his thigh against his brother’s cock. Seto groans into his mouth, bucking up against him and sending water cascading over the side of the bath. 

Mokuba grins into their kiss before he breaks it. 

“Will you fuck me tonight, Seto?” he asks. 

They’re close enough that he can see Seto’s pupils bloom black at the thought, dilating until only the thinnest ring of blue remains. He licks his lips and Mokuba knows that he’s won - even though Seto _still_ asks him if he’s sure. 

“I’m not going to regret it, you know,” he says, and barely brushes his lips over Seto’s in a kiss. “I want you.”

He’s ready - he _knows_ he’s ready - and the thought of finally having Seto inside of him is making him feel lightheaded. 

He’s only ever had Seto’s fingers before. Anything more than that has been relegated to a nebulous “when you’re a bit older” like he’d ever change his mind. Usually they stick to mutual blow jobs, and Mokuba _loves_ those, but the one time Seto stretched him open on those long, glorious fingers was one of the best experiences of Mokuba’s life. 

“Please, Seto?”

Seto has never been able to resist him when he asks like that. Mokuba _tries_ not to abuse the privilege too often, he honestly does, but this is different. Seto huffs at him, rolls his eyes, and sits up. 

“Not here,” he says. “Bed.”

...

Their apartment at the top of the Kaiba building is infinitely better than the mansion had been. For a start, they can choose who to let in - and so far, the only other person who has access is a maid from a private cleaning company. They handle the rest themselves. Second, in this sanctuary, they aren’t kept in separate wings and reduced to stealing private moments. They share a room, a bed, a life. Mokuba keeps a separate bedroom for the sake of the maid and he makes sure to make the bed look slept in by lying on it to do his homework. 

Their bed is big. It’s comfortable. It’s bizarrely imposing right now. 

He swallows nervously, looking at the deep blue of their duvet. He’d felt so confident in the bath, with Seto pliant and willing beneath him. Now, though, he feels as if his feet can’t move; as if his heart has leapt up into his throat and won’t budge. He can feel Seto behind him, feel the heat radiating from his skin. 

He still jumps when Seto touches him. Just a hand on his shoulder, but he jumps all the same. 

He hears his brother sigh. “You don’t have to do this. You know I won’t mind, right?”

Mokuba closes his eyes briefly. “I know, Seto,” he says. 

He doesn’t know why he’s suddenly so nervous. This is _Seto_. His brother, his husband, his _life_. He’s not in any danger. He’s been planning this for months - and sure, so Pegasus and the Big Five effectively destroyed any and all of his _actual_ plans for their wedding anniversary by shoving him in a dungeon and locking his soul away, but that doesn’t mean that he wasn’t wanting this to happen. Anticipating it, even. 

“Do you think it hurts?” he asks, because the people on the internet sometimes act like it does and Mokuba has very limited experience otherwise. 

“Did it hurt when I fingered you?” Seto asks back. He rubs gently at Mokuba’s shoulder and the back of his neck. 

Mokuba shakes his head. It hadn’t. It had been a stretch, sure, and he’d ached a little the next day, but it hadn’t hurt. He leans back against Seto, tilts his head to look up at him. 

“You want this too, right, big brother?” he asks. 

Seto’s lips twitch into that sweet, private smile that only Mokuba gets to see. It’s the same smile he’d worn the day they promised themselves to each other. It’s the smile Mokuba adores more than anything because of how rare it is, to see Seto truly happy. 

He lets that adoration fill him until he feels like he can move again, like he can float all the way to the bed. Then, he turns in Seto’s hold and takes his brother’s hand and leads him there, hardly even feeling the scuff of carpet under his bare feet. 

He’s still nervous, but the confidence he’d had in the bath has returned. 

He flops onto his back on the mattress with a soft _whumph_ and he drags Seto down over him. His brother is gorgeous like this - all toned skin and tousled hair and a promising bulge tenting the front of his towel. Seto’s eyes are dark and hungry, but he’s still wearing that sweet little smile; still letting Mokuba take the lead. Mokuba slides his hands over Seto’s chest and up the back of his neck, and he drags Seto down into a kiss, arching up against him as he does. 

Seto licks into his mouth, just like he wanted. When they kiss like this it feels like they're the only ones left in the whole world, and Mokuba _loves_ it. 

He parts his legs, letting Seto settle his weight between his thighs. He can feel Seto’s erection pressing against his own - longer, thicker - and sparks flare in his belly at the thought of having it inside of him, splitting him open. He arches, pushing his hips up, and he feels the low rumble of Seto’s laughter in his chest. One elegant hand slides downward, tracing lines of heat down his chest and belly to tug at the towel bunched around his waist. Seto breaks their kiss, moving lower, licking a path down Mokuba’s neck. 

He doesn’t bite; he won’t leave marks where someone might spot them and ask questions. 

“Roll over,” Seto murmurs. His voice is deeper than usual, little more than a growl. It makes Mokuba dizzy sometimes to think of the effect he has on his brother. It’s a heady kind of power that he has over Seto, but - 

“I wanted to see you,” he says. 

Seto smirks at him. “We can do that,” he says, “but you need to turn over first.” 

Mokuba frowns a little, but does as he’s told. And promptly yelps when Seto boosts him further towards the middle of the bed, clambering in after him. 

“Seto!”

“Lift your hips, little brother,” Seto orders. It’s his CEO voice, darkened with lust, and Mokuba obeys in an instant, raising his hips from the bed and parting his legs. He turns his head, peeking at Seto over his shoulder. His brother looks... He’s looking at Mokuba like he’s beautiful, perfect, and Mokuba’s heart lodges in his throat again. 

One of Seto’s hands slides around his hips to support his belly while the other positions a pillow under him. Mokuba relaxes onto it, thrusts against it for the friction only for Seto to stop him with a soft, huffed laugh and a squeeze of his hip. He freezes in place, gripping the sheets beneath him and biting his lip, still watching over his shoulder as Seto settles onto the bed behind him. He watches as Seto shifts closer, feels the mattress dip under his weight, and feels breath gust hot and wet over his lower back.

He twitches when the first kiss is pressed to the base of his spine. It’s a simple gesture, but it sends shocks of pleasure rocketing up his spine. He sucks in a harsh breath and presses his hips hard against the pillow beneath him. His eyes scrunch shut as Seto moves lower, kissing and licking, spreading Mokuba’s thighs further apart. Mokuba can’t stop the whine that escapes him the first time Seto’s tongue slips over his hole. A gentle, wet lap against furled muscle. He gasps when Seto does it again – again and again, hot and wet and _wonderful_.

He starts to relax, losing himself to the pleasure of his brother’s tongue. He finds himself arching back into it. Seto’s hand shifts to the small of his back, trying to hold him still, but Mokuba keeps moving. He can’t help it. It’s the same sort of pleasure he’d felt when Seto used his fingers, but it’s completely different at the same time. There’s wet, slopping noises making the hair rise on the back of his neck and his skin prickle. It’s _filthy_ , and there’s a part of him – a part that’s rapidly losing coherency – that can’t believe Seto’s doing this at all. 

He cries out when the movement changes; comes hard onto the pillow when Seto thrusts his tongue inside of him. He sobs as Seto keeps going, keeps fucking him through it; white spots dance behind his eyelids and he can feel tears running down his cheeks. It feels so good. So, so good.

Seto takes his time working him open. He swaps out his tongue for his fingers, presses gentle bites to the swell of Mokuba’s arse. Nothing hard enough to bruise or make marks for longer than a moment, but just enough to create a sting of pain and make Mokuba’s belly quiver. He’s hard again by the time Seto finally, finally rolls him onto his back, and the way that Seto looks at him – the expression on his face as he takes in the trails of Mokuba’s tears and the come smeared over his abdomen – damn near makes him come for a second time.

His breath hitches as Seto presses three fingers back into him. The angle is different like this. Not quite as deep, but somehow far more intimate. 

“I’m ready, Seto,” he says, and he can’t bring himself to care that it comes out more as a plea than a statement. He’s _past_ ready. He needs Seto so much right now that it _hurts_.

For once, Seto doesn’t ask him if he’s sure. He swallows instead. Nods once. Pulls his fingers out, leaving Mokuba feeling empty and bereft. He can feel his body twitching in response to the sudden loss, and he whines softly, lifting his hips from the pillow.

Seto swears under his breath. Mokuba beams up at him, watching hungrily as Seto coats his dick with lubricant, gripping the base of his shaft to try and take the edge off. His foreskin is drawn back, revealing the wet, purpling head, and Mokuba’s mouth waters with the knowledge of how he tastes. Nerves make his belly flutter as Seto leans over him, guiding himself to Mokuba’s entrance. He forces himself to relax, tries to distract himself by reaching up and touching Seto’s chest, his shoulders, his face. Seto glances up at him, eyes dark. Mokuba can hear his breath shaking as he exhales; can feel the pressure of his cock as he begins to push inside.

Even after all the preparation, it’s still a stretch. Mokuba cries out, the noise punched from him as Seto keeps pushing in, splitting him open. He feels –

Massive. Incredible. Overwhelming. He’s too much and he’s still pushing in and Mokuba knows that he’s crying again; can feel tears leaking from the corners of his eyes. He wraps his legs around Seto’s hips, digs his heels into his brother’s arse to pull him closer, deeper. It’s _perfect_. He’s filled and surrounded and drowning in Seto and it’s _everything_.

Seto leans down over him, kisses his tears away. He’s murmuring under his breath. Soothing nonsense just like he used to when they were younger and he was patching up Mokuba’s scrapes. Only now he’s telling Mokuba how good he is, how hot and tight and beautiful he is, and Mokuba can barely breathe for how good it feels to be filled like this, held and worshipped like something precious.

He claws at Seto’s back as his brother begins to pull out. He doesn’t want to be empty again. But Seto thrusts back in, hard, and Mokuba cries out again with the force of it. It’s rougher than he thought it would be. He can feel his brother trembling slightly as he moves and he knows that this isn’t going to last long. Seto’s too close to coming to even try and go slower. He clings to him desperately as Seto sets an unforgiving pace, fucking into him hard and deep, lifting Mokuba’s hips off the pillow with every thrust. He shifts a little, grasps one of Mokuba’s thighs and pushes it up towards his chest, and the following thrust makes white spark across Mokuba’s vision again. 

He can hear someone screaming Seto’s name. It barely registers that it’s him. He’s barely even aware of his second orgasm when it hits, spattering streaks of white fluid between their bodies. Seto makes a wounded noise, catching Mokuba’s lips in kiss as he keeps moving, keeps thrusting harder and deeper until he shudders. Mokuba gasps into his mouth as Seto comes inside of him, filling him further – dripping out of him when Seto pulls back. 

He looks up at his brother – his husband – and feels… _right_.

“Happy anniversary, Seto,” he whispers.

...

He wakes up to the familiar sound of typing. There’s a dull ache radiating from his arse up into his lower back, but even with that unfamiliar soreness, he feels warm and content. Happy. Seto is next to him still, sitting up in their bed with his back to the headboard and his laptop propped against his knees. He’s typing one-handed; the other is tangled in Mokuba’s hair, twisting long strands around his fingers. 

Seto tries not to come across as a fidgety person, but Mokuba knows his secret. 

He presses a morning kiss to Seto’s hip and wiggles up as much as he can without dislodging Seto’s hand in order to peer at the screen. The movement makes him wince slightly, but it isn’t _too_ bad. He can definitely cope - especially since he _really_ wants a repeat performance. He cuddles happily into Seto’s side, resting his head on his chest, content for a moment to just listen to his brother breathe. 

Then, he looks at the screen 

Seto has his email browser open. It takes Mokuba a moment to parse through the legalese, but once he’s done he can’t quite hide the pleaser little snigger that escapes him. 

“Feeling vicious, huh, Seto?”

Seto hums softly in agreement. By the look of his email, the board members who attempted to assassinate him (twice) will be tied up in litigation for the rest of their lives, bankrupted and blacklisted - if not outright imprisoned. Their great-grandchildren will still be paying their legal fees. 

It’s so beautifully vicious it brings a tear to Mokuba’s eye. 

Seto signs the email with a flourish and doesn’t even hesitate before turning the laptop towards him. 

“Do the honours?” he murmurs, pressing his face into the nest of Mokuba’s hair. 

Mokuba has never clicked the _send_ button faster.


End file.
